紙漿污泥焚化爐飛灰部分取代混凝土細粒料之可行性研究

In Taiwan, the total amount of sludge discharged in 2020 accounted for 8.69% of the total amount of general industrial waste. Currently, incineration is considered an effective method to reduce the volume and decompose the organic matter in the sludge. In this study, Paper Sludge Fly Ash (PSFA) was used to replace fine aggregate in mortar and concrete by different proportions. This research evaluates the feasibility of replacing fine aggregate with PSFA. By investigating the properties of fresh, hardened, durability, and microanalysis of mortar and compressive strength of concrete. It was found that the workability of mortar is significantly affected when using PSFA to replace a part of fine aggregate. When the PSFA replacement ratio is 25% and the water-cement (W/C) ratio is 0.50, the 90 days compressive strength of mortar can reach 101.7 MPa, but the drying shrinkage also increases. Besides, PSFA can hydrate and produce C-S-H colloid, and the unhydrated particles can also produce a filling effect to improve the compactness of concrete. In addition, PSFA can also improve the microstructure of the interfacial transition zone (ITZ) in concrete, and reduce the pore between the coarse and fine aggregates, which can significantly improve the compressive strength of concrete.